Simple squamous epithelium can be studied by looking at cells which line blood and lymph vessels. These flattened cells are called endothelial cells . The nuclei are frequently found protruding into the lumen of the vessel. Observe the numerous large blood vessels present in the periphery of this section. Simple squamous epithelium is also the outer covering of the uterine tube which is termed the mesothelium

SIMPLE CUBOIDAL EPITHELIUM:Kidney.

Simple cuboidal epithelium is prominent in the cortex and medulla of the kidney. Proximal convoluted tubules , distal convoluted tubules , and collecting ducts are examples of simple cuboidal epithelium

SIMPLE COLUMNAR EPITHELIUM:

[center]Locate a large fingerlike projection at the surface of the organ (this is an intestinal villus ). Observe that the projection has an internal component and a surface. The surface of each villus is covered with simple columnar epithelium . The free surface of these cells has very tiny projections called microvilli , which are specialized for absorption (absorptive cells). Numerous mucus-secreting cells, known as goblet cells because of their shape, are dispersed between the absorptive cells. In the lab or on Hippocrates, locate an electron micrograph of an intestinal absorptive cell and compare the details which you see in your light microscope with those seen on electron micrographs

Duodenum

PSEUDOSTRATIFIED CILIATED COLUMNAR EPITHELIUM: Trachea

Note the ciliated, pseudostratified columnar epithelium lining the tracheal lumen. This epithelium is commonly referred to as "respiratory epithelium". Compare cilia with the microvilli on Slide 52. Note that the cilia are much longer. Study the ultrastructure of cilia and microvilli in electron micrographs.

Epididymis, efferent ducts

Distinguish between the epididymis and the efferent ducts in this slide by the appearance of the lumen in each organ. The epididymis has a smooth, even epithelium lining its lumen; while the efferent ducts are more scalloped in appearance. Both are examples of pseudostratified columnar epithelium. Especially note the stereocilia (long microvilli) of the epididymis